#region The MIT License
// The MIT License
// 
// Copyright (c) 2009 octalforty studios
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#endregion
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.Diagnostics;
using System.IO;
using System.Text.RegularExpressions;

using octalforty.Componento.ComponentModel.Installation.Web;
using octalforty.Componento.Util;

namespace octalforty.Componento.ComponentModel.Installation
{
    [ManifestProvider()]
    public class HttpRepositoryManifestProvider : IManifestProvider
    {
        #region Private Fields
        private IWebRequestFactoryService webRequestFactory;
        #endregion

        #region Public Properties
        /// <summary>
        /// Gets or sets a reference to the <see cref="IWebRequestFactoryService"/>.
        /// </summary>
        [Import()]
        public IWebRequestFactoryService WebRequestFactory
        {
            [DebuggerStepThrough]
            get { return webRequestFactory; }
            [DebuggerStepThrough]
            set { webRequestFactory = value; }
        }
        #endregion

        #region IManifestProvider Members
        /// <summary>
        /// Verifies whether current <see cref="IManifestProvider"/> can retrieve manifest from <paramref name="uri"/>.
        /// </summary>
        /// <param name="uri"></param>
        /// <returns></returns>
        public bool CanProvideManifestFrom(Uri uri)
        {
            return uri.Scheme.ToLowerInvariant() == "http";
        }

        /// <summary>
        /// Retrieves <see cref="Manifest"/> from <paramref name="uri"/> for package <paramref name="packageName"/> with
        /// version requirement <paramref name="versionRequirement"/>.
        /// </summary>
        /// <param name="uri"></param>
        /// <param name="packageName"></param>
        /// <param name="versionRequirement"></param>
        /// <returns></returns>
        public Manifest GetManifest(Uri uri, string packageName, VersionRequirement versionRequirement)
        {
            Regex r = new Regex(@"^(?<PackageName>[^/][^\s]+)\s+((?<Version>\d+(\.\d+){0,3}))?\s*(?<Uri>.+)$", RegexOptions.Compiled | RegexOptions.Multiline);

            IWebRequest webRequest = WebRequestFactory.CreateWebRequest(WebRequestMethod.Get, new Uri(uri, "packages.cpri"));
            List<PackageReference> prs = new List<PackageReference>();

            Console.WriteLine("Downloading from {0}", uri);

            using(IWebResponse webResponse = webRequest.GetResponse())
            {
                using(Stream responseStream = webResponse.GetResponseStream())
                {
                    Console.WriteLine("Downloading {0:N1} Kb", webResponse.ContentLength / 1024.0);

                    ParsePackageIndex(responseStream, r, prs);
                } // using
            } // using

            prs.Sort(delegate(PackageReference pr1, PackageReference pr2)
                { return pr2.Version.CompareTo(pr1.Version); });

            PackageReference pref = prs.Find(delegate(PackageReference pr)
                { return string.Compare(pr.PackageName, packageName, StringComparison.CurrentCultureIgnoreCase) == 0 /*&& versionRequirement.Matches(pr.Version)*/; });

            return pref == null ?
                                    new Manifest(null) :
                                                           new Manifest(pref.Version, pref.Uri);
        }

        private void ParsePackageIndex(Stream responseStream, Regex r, List<PackageReference> prs)
        {
            StreamUtil.ReadLines(responseStream, 
            delegate(string s) { return r.IsMatch(s); }, 
            delegate(string s)
                {
                    Match m = r.Match(s);

                    Version version = m.Groups["Version"] == null || string.IsNullOrEmpty(m.Groups["Version"].Value) ?
                        new Version(0, 0) :
                        new Version(m.Groups["Version"].Value);
                    prs.Add(new PackageReference(m.Groups["PackageName"].Value,
                                                 version,
                                                 new Uri(m.Groups["Uri"].Value)));
                });
        }
        #endregion
    }
}